<?php
namespace AAP\Modules\Images;

use AAP\Modules\Logs\Logger;

defined('ABSPATH') || exit;

/**
 * DuckDuckGo image search (no API key required).
 *
 * The query itself is produced by the AI (see AiService::image_plan), so the
 * blog owner's image instructions influence what is searched.
 */
final class DuckDuckGo {

    private int $timeout;

    public function __construct(int $timeout = 30) {
        $this->timeout = max(10, $timeout);
    }

    /**
     * @return string[] image URLs (best first)
     */
    public function search(string $query, int $limit = 10): array {
        $query = trim($query);
        if ($query === '') {
            return [];
        }

        $encoded = urlencode($query);
        $token   = $this->vqd($encoded);

        if ($token === '') {
            Logger::warn('DuckDuckGo: vqd token not found for "' . $query . '".', 'images');
            return [];
        }

        return $this->fetch($encoded, $token, $limit);
    }

    private function vqd(string $encoded_query): string {
        $response = wp_remote_get(
            'https://duckduckgo.com/?q=' . $encoded_query . '&iax=images&ia=images',
            [
                'timeout'    => $this->timeout,
                'user-agent' => 'Mozilla/5.0 (compatible; automatic-ai-posts/2.0)',
            ]
        );

        if (is_wp_error($response)) {
            Logger::warn('DuckDuckGo: token request failed: ' . $response->get_error_message(), 'images');
            return '';
        }

        $body = (string) wp_remote_retrieve_body($response);

        if (preg_match('/vqd=([\d-]+)/', $body, $m)) {
            return $m[1];
        }

        return '';
    }

    /**
     * @return string[]
     */
    private function fetch(string $encoded_query, string $token, int $limit): array {
        $url = add_query_arg([
            'l'   => 'us-en',
            'o'   => 'json',
            'q'   => $encoded_query,
            'vqd' => $token,
            'f'   => ',,,,,',
            'p'   => '1',
        ], 'https://duckduckgo.com/i.js');

        $response = wp_remote_get($url, [
            'timeout' => $this->timeout,
            'headers' => [
                'Referer'    => 'https://duckduckgo.com/',
                'User-Agent' => 'Mozilla/5.0 (compatible; automatic-ai-posts/2.0)',
            ],
        ]);

        if (is_wp_error($response)) {
            Logger::warn('DuckDuckGo: image request failed: ' . $response->get_error_message(), 'images');
            return [];
        }

        $data = json_decode((string) wp_remote_retrieve_body($response), true);

        if (!isset($data['results']) || !is_array($data['results'])) {
            Logger::warn('DuckDuckGo: response without results.', 'images');
            return [];
        }

        $urls = [];
        foreach ($data['results'] as $result) {
            $image = (string) ($result['image'] ?? '');
            if ($image !== '') {
                $urls[] = $image;
                if (count($urls) >= $limit) {
                    break;
                }
            }
        }

        return $urls;
    }
}